On Tue, Mar 07, 2023 at 06:38:59AM +0000, Tian, Kevin wrote: > > From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > > Sent: Friday, March 3, 2023 2:58 PM > > > > > What should we return here anyhow if an access was created? > > > > iommufd_access->obj.id. should be fine. Is it? > > Thinking more I'm not sure whether it's a good idea to fill the > dev_id field with an access object id and then later confuse > the user to get an -ENOENT error when trying to allocate a > hwpt with an access object id. > > How can user differentiate it from the real error case where > invalid iommufd object is used? > > It sounds clearer to return dev_id only when there is a true > device object being created by the bind_iommufd cmd. Then > the user can use it to decide whether to further attempt > dev_id related cmds. It means we can never return an access_id I don't think this is a problem, the first thing userspace should do is a get info to the dev_id which is needed to learn which iommu driver is running it, if that returns EOPNOTSUPP then it isn't a physical iommu device. Jason
